The current way the window industry manufactures vinyl or plastic windows, first involves the welding together of the corners of the vinyl window. They do this by heating the corners to melt the vinyl and then they press the corner pieces together to form a joint. When the vinyl hardens and bonds the corner this is typically known as welding. In the known method an aluminum platen is used and is heated to approximately 400-500 degrees F. to heat the separate vinyl pieces to form a vinyl corner. The vinyl pieces are pressed against the heated platen to melt the end of each vinyl piece. The corner pieces being welded are usually formed with and end 45 degree surface. To perform this method one has to use a release material between the vinyl piece and the platen, so as to not have the vinyl stick to the platen which is typically constructed of a metal such as aluminum.
Currently there are basically two ways the industry accomplishes this release material or layer. One way is to provide the platen with a mechanism to secure a Teflon (polytetrafluoroethylene) coated fiberglass pad to the platen. Only about 10% of the welding machines have this option. Another way that is most popular is where one secures a Teflon coated fiberglass tape. Such tapes are used in approximately 90% of the applications. In both situations one has to cut the Teflon coated fiberglass material into separate pieces to cover the platen. In order to get a good weld the surface of the platen has to be perfectly smooth. If something gets behind the Teflon coated fiberglass pad or tape there will be a defect in the weld and this will cause the window to be rejected. Successive contact of the vinyl pieces with the platen at the work area can cause a tearing of the release material.
Currently, the only way one can purchase the tape is with the adhesive covering all of one side of the tape. When the tape or pad becomes worn the weld deteriorates and the pad or tape then has to be replaced. It is worn when the pad or tape will tear and vinyl leaks to the aluminum platen. This typically forms a lump that, in turn, causes a rejected window component. When replacing a worn tape, upon peeling the tape off the platen, most of the time the adhesive on the tape sticks to the aluminum platen. This is an undesirable situation. This sticking to the platen is because the adhesive sticks readily to the aluminum platen. Then the adhesive causes a lump that has to be removed. This means that extra time needs to be taken to clean each platen. This can be very costly in labor and machine down time.
Accordingly, it is object of the present invention to overcome the above prior art drawbacks to provide an improved system and associated method for fabricating the corner of a plastic window frame in which the process can be carried out more efficiently.
Another object of the present invention is to provide an improved system and associated method for fabricating the corner of a plastic window frame in the manufacture of a vinyl window, and in which a greater number of window frames can be fabricated before the platen has to be cleaned.